Effect of Capsular Tension Ring on the Accuracy of Nine New-Generation IOL Formulas in Long Eyes

Purpose To investigate the effect of capsular tension rings (CTRs) on the accuracy of nine new-generation intraocular lens (IOL) formulas in long eyes. Methods A total of 106 eyes (106 patients) with CTR (CTR group) and another 106 eyes (106 patients) without CTR (NCTR group) were analyzed. The differences in mean prediction error, standard deviation, mean absolute prediction error (MAE), median absolute prediction error (MedAE), root mean square absolute prediction error (RMSAE), and percentage of eyes within ±0.25, ±0.50, ±0.75, ±1.00, and greater than ±1.00 diopter (D) were compared. Results In the CTR group, only the Hoffer QST and VRF-G formulas showed significantly lower MedAE compared to the NCTR group. There was no statistically significant difference found among other formulas. The VRF-G and Hoffer QST formulas had lower MAE (0.351 to 0.367) than the Kane (0.469) ( P < .05). The K6 and Pearl-DGS formulas had higher MAE (0.441 to 0.452) than the Zhu-Lu (0.351) and Emmetropia Verifying Optical (EVO) 2.0 (0.377) ( P < .05). In the NCTR group, the Zhu-Lu and RBF 3.0 formulas had lower MAE (0.340 to 0.411) compared to the Kane (0.477) ( P < .05). The Zhu-Lu and EVO 2.0 formulas also had lower MAE (0.340 to 0.363) than Pearl-DGS (0.429) ( P < .05), and the EVO 2.0 had lower MedAE (0.273) than the Kane (0.433) ( P < .05). The percentage of eyes within ±0.50 D (76 to 85, 71.70% to 80.19%) of the RBF3.0, K6, EVO 2.0, and Zhu-Lu formulas were higher than Kane (53.77%) ( P < .02). Conclusions CTR implantation does not improve the refractive prediction accuracy of the most new generation IOL formula. The Zhu-Lu formula is recommended for use in long eyes, regardless of CTR implantation. [ J Refract Surg . 2025;41(2):e114–e119.]